This invention relates to specific ternary, quaternary and pentanary halocarbon blends as described herein. Such blends are useful as refrigerants, heat transfer media, fire extinguishing agents, gaseous dielectrics, expansion agents, aerosol propellants and power cycle working fluids. These blends are potentially environmentally safe substitutes for dichlorodifluoromethane (CFC-12).
In refrigeration applications, and more specifically, in automobile air conditioning systems, refrigerant may be released to the atmosphere through leaks, such as through shaft seals, hose connections, solder joints, etc. Additionally, refrigerant may also be released to the atmosphere during equipment repair and equipment damage, such as automobile accidents.
Worldwide concern about stratospheric ozone depletion has resulted in a concerted search for alternative compounds which have lower ozone depletion potentials than CFC-12 which is the most widely used refrigerant. Its future use is expected to be reduced significantly because of its relatively high ozone depletion potential.
Most currently produced commercial refrigerants are either pure fluids or azeotropes. Many of these refrigerants have ozone depletion potentials.
Some nonazeotropic mixtures may also be used as refrigerants but they have the disadvantage of fractionating when a portion of the refrigerant charge is leaked or discharged to the atmosphere. Should these nonazeotropic mixtures contain a flammable component, they could either become flammable themselves or release a flammable component to the atmosphere. Refrigeration equipment operation could be affected adversely because of compositional and vapor pressure changes.
What is needed, therefore, are substitute refrigerant blends which maintain refrigerant properties over wide compositional ranges, and also have significantly reduced ozone depletion potentials.